This invention relates to an air mass flow controller in general, and more particularly to an air mass flow controller valve for fuel cells containing several flow passages, each controlled independently by an associated electromechanical actuator.
It is believed that a fuel cell consists of two electrodes sandwiched around an electrolyte. It is believed that oxygen, from air, passes over one electrode and hydrogen, from one or more storage device, passes over the other electrode, that, in a chemical reaction, generates electricity, water and heat.
The electricity generated by a fuel cell is believed to be regulated at least in part by the amount of air or oxygen delivered to the fuel cell. Where the fuel cell includes a plurality of fuel cell units, it is believed that there is a need to accurately regulate the amount of air or oxygen delivered to each fuel cell unit.
An air mass flow controller valve for fuel cells that includes an inlet, a plurality of first and second passages, and at least two air mass sensors, two seat positions, two closure members, and two actuators. The inlet is disposed along a first axis, and is coupled to a housing. The housing has a first bank of outlets disposed along a second axis and a second bank of outlets disposed along a third axis. The first and the second bank of outlets are in fluid communication with the inlet. The plurality of first passages are coupled to the first bank of outlets, and the plurality of second passages are coupled to the second bank of outlets. One of the at least two air mass sensors is disposed proximate to the plurality of first passages, and the other of the at least two air mass sensors is disposed proximate to the plurality of second passages. One of the at least two seat portions is disposed between the plurality of first passages, and the other of the at least two seat portions is disposed between the plurality of second passages. One of the at least two closure members is disposed proximate the plurality of first passages, and the other of the at least two closure members is disposed proximate the plurality of second passages. Each closure member is movable to a plurality of positions. A first position permits air flow between the inlet and each of the plurality of the first and second passages. A second position prevents communication between the plurality of the first and second passages. The at least two actuators are coupled to a respective one of the at least two closure members and are responsive to a respective one of the at least two air mass sensors in each of the plurality of the first and second passages to move a respective one of the at least two closure members between the first and second positions.
The present invention also provides a method of distributing metered airflow from an inlet to a plurality of first and second passages in a fuel cell. Each passage of the plurality of first and second passages is provided with an air mass sensor that provides a signal, which indicates measured air amount flowing in each passage of the plurality of first and second passages, a housing, and a plurality of closure members. Each closure member is contiguous to a seat portion and disposed in a respective passage of the plurality of first and second passages. Each closure member is movable by an actuator between a first position to permit flow and a second position to prevent flow. The method includes flowing air through the inlet, flowing air through the housing, determining an air amount in each passage of the plurality of first and second passages, and metering the air amount provided to each passage from the inlet as a function of a desired air amount and the air mass amount determined in each channel.